Method and structure for reclosable containers



April 19, 1966 KAKUJl NAlTO METHOD AND STRUCTURE FOR RECLOSABLECONTAINERS 3 Sheets-Sheet 1 Original Filed Feb. 15, 1961 [Hz En [43F Aril 19, 1966 KAKUJI NAlTO 3,

METHOD AND STRUCTURE FOR RECLOSABLE CONTAINERS Original Filed Feb. 15,1961 3 Sheets-Sheet 2 III/II/ZI/I/I/d A ril 19, 1966 KAKUJI NAITO3,246,672

METHOD AND STRUCTURE FOR RECLOSABLE CONTAINERS Original Filed Feb. 15,1961 3 Sheets-Sheet 3 fnz s'nfar flax y 4 0/70 United States Patent3,246,672 METHOD AND STRUCTURE FOR RECLOSABLE (IONTAINERS Kakuji Naito,Kawasalri-shi, KanagaWa-ken, Japan, as-

signor to Kabushiki Kaisha Seison Nikon Sha, Tokyo, .lapan, acorporation of Japan Original application Feb. 15, 1961, Scr. No.89,546. Divided and this application Get. 23, 1963, Ser. No. 325,197

7 Ciairns. (Cl. 138118) This invention relates to bags and tubes formanufacturing bags made of synthetic resin, wherein have been formedintegral with the bag material at the inner surface of the bag mouthvis-a-vis each other, a male rib and a female rib which are provided asto be occlusive with respect to each other, the present applicationbeing a division of my copending application Serial No. 89,540, filedFebruary 15, 1961.

In making the tubular bag material, the bag material is molded into along continuous tube, which is obtained by extruding from a conventionalextruder a synthetic resin under heated state upward through an annularextrusion gap to form continuously a tubular body in which are formed bymeans of incision-like molding grooves provided in a section of theannular extrusion gap simultaneously in the inner surface thereof raisedmale and female ribs parallel with the line of generation of the tubularbody. Then, in transporting this while clasped in a state of flatness bymeans of a pair of rolls provided at the top of the apparatus, air isfirst blown from the aforesaid molding mold into the tubular bag body tomaintain the same in a swelled state between the mold and the aforesaidrolls and by concurrently blowing in cold air uniformly from air inletpipes surrounding the tubular body against the tubular body maintainedin the swelled state the film is cooled uniformly. The tubular body isthen guided for engaging the occludent means.

The bag material which is now flat and maintaining its occluded statecan be finished into individual bags by cutting followed by sealing thecut edges. In actual practice, however, owing to the necessity ofaccomplishing printing of such as trademarks, trade names, etc. on thebag surface, the bag material that has been formed in a flat andcontinuous state, as described hereinabove, is first wound up on a reel,transferred to the printing step where after printing it is rewound onthe reel and thereafter cut and the cut edges simultaneously sealed.

The mode of practicing the invention will be described concretely belowwith reference to the accompanying drawings, in which:

FIG. 1 is a detailed front elevation of that section of a mechanismwhich continuously molds the bag material;

FIG. 2 is a top plan view of a mold section for making the bag material;

FIG. 3 is a cross-sectional view of the bag material taken along linesTIL-III of FIG. 1;

FIG. 4 is a top plan view showing the bag material subsequent to itshaving been occluded;

FIG. 5 is a top plan view showing separate bags formed on a conveyorbelt after having been cut from the tube material and cross sealed;

FIG. 6 is an enlarged view in section of the resultant synthetic resinbag;

FIG. 7 is an enlarged view in section showing a modification of theoccluding ribs;

FIG. 8 is a cross-sectional view showing the bag material in which twosets of occluding ribs have been formed;

FIG. 9 is a descriptive drawing showing the above bag material in itsflattened form and the location where it is to be cut; and

FIG. 10 is an enlarged detailed fragmentary sectional view of theinterlocking occludent means.

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As shown in FIGURES 1 and 2 an outer mold 1 has a core 3 with a shapednarrow annular extrusion gap 2 therebetween. Plastic is forced throughthe gap 2 by extruder mechanism not shown, and air introduced into atube extruded through the gap 2 through a pipe 4. As illustrated the gapis preferably of uniform width to form a tube of film of uniformthickness. There are formed molding grooves 7 and 8 in the outer surfaceof the core 3 communicating with the extrusion gap 2 for forming maleand female ribs 9 and 10 integrally with the bag body 6.

Directly above this mold (FIG. 1) there is provided a pair of deliveryrolls 11, 11 disposed in lateral fashion facing each other for claspingand delivering in a fiat state the tubular bag body 6 that is extrudedfrom the mold. Air is blown in small amounts into the tubular bag body 6from the bottom through the aforesaid air inlet pipe 4, with the toppart of the bag body 6 being held together by means of the deliveryrolls 11, 11. The bag body 6 is swelled or inflated and maintained in atubular shape. Below the rolls 11, 11 there is provided a pair of guideplates 12, 12 facing each other in roof fashion whereby the shoulderportion of the bag body 6 swelled into a tubular shape is guided and isgradually pressed flat as shown in FIG. 1 and passes between the rolls11, 11.

At that part of the apparatus where the tubular bag body 6 ascends, acold air discharge section, not shown, is provided. Air is appropriatelysupplied and is blown against the outer surface of the bag body 6 toremove heat from the freshly molded film and thus cool the same.

The interlocking elements 9 and 10 are aligned and interlocked to holdthe opposed sides of tube material together. The bag body 6 is thusmolded into a flat belt-like shape. In actual practice, however, sincein most cases printing of such as trademarks, trade names, etc. areaccomplished, it is perhaps convenient to first wind up the bag materialin this state by guiding the same to a windup reel.

In the hereinabove-described apparatus, the cross-sectional shape of themale and female ribs suitable for occlusion of the bag body 6 can beobtained by suitably designing the configuration of the molding grooves7, 8. The cross-sectional shape of these male and female elements 9, 1%may be suitably determined in acordance with the uses to which the bagsare to be put. For example, as shown in FIG. 7, for a container to beused for fine powders the ribs may be so formed so that the labialsection of the female rib 9 is turned inward along the length of the ribwhile the male rib 10 is formed arrowhead shaped. In addition,regardless of the shapes of the male and female ribs, when two setsthereof are formed facing each other, as illustrated in FIG. 8, andsubsequently out along line 0-0 midway between the two when the bag bodyhas been flattened as in FIG. 9, two bags are obtainable at the sametime. FIG. 10 shows the rib and groove elements 9 and ltl in greaterdetail.

The incisions 7 and 8, which constitute a set of the molding grooves areincised in a part of the circumference of the core 3 with the shape ofthe grooves being of a wide variety. Since their positions will bedetermined by the size of the mold, by providing molding plates for thecore of the same size having a wide variety of incisions and selectivelyusing the same, it becomes possible to form ribs of any desired shape.

The bag body that has been molded as described hereinbefore is thenprocessed further in the following manner. First, the male and femaleribs that have been formed integrally in the bag body are occluded, thenafter flattening, to the surface of the bag body is imparted, ifrequired, the desired printing and thereafter by using an apparatus tobe described hereinafter the bag body is cut into the individual bag andsimultaneously therewith the cut edges of the bags are heat sealed.

In a position forward of a belt 203, rollers 2G7, 263 are disposedlongitudinally, around which an endless conveyor belt 209 is mounted.The tip of the bag body 6 which is delivered forth, FIGURE 5, is made tobe transferred smoothly from the belt 203 to the radially moving part ofthe conveyor belt 209. The surface of this conveyor belt 209 by beingimparted a layer of such as, for example, silicon rubber is maintainedso that the bag body does not stick to the surface of the conveyor beltas a result of operations such as cutting and heat sealing. In addition,by suitable determination of the rotating speed of the rollers 207, 208,the rate of travel of the conveyor belt 209 is made to be greater thanthat of the bag body 6. An electro-thermic means is provided, whichmakes possible simultaneously with the cutting of the bag body the heatsealing of the cut edges. A pressure plate 226 is provided. Theindividual bags are severed and sealed as shown in the copendingapplication Serial 89,540. Further, at 237 is a set of superposed beltsthat have been provided forward of the conveyor belt 209 and have beenprovided for the purpose of removing the bags that have been conveyed bythe conveyor belt 209.

When the continuous tube is cut into predetermined widths starting atone end and the cut edges thereof are heat sealed, as a result of thefact that a unit width of a bag body leaves the bag body material and isplaced independently upon the top of the conveyor belt 209, the cutedges become spaced apart automatically from each other for an Sdistance.

In using these bags, by cutting the bags at the top 1, FIG. 6, andopening up the engagement of the male and female ribs, the bag is readyto be filled with whatever it is to be filled with. After the bags arefilled the male and female ribs 9, 10 are again occluded, and ifnecessary, the mouth which was opened by cutting may be again sealedusing a heat sealer.

While the invention has been described with particular reference tospecific embodiments, it is to be understood that it is not to belimited thereto, but that changes may be made therein without departingfrom the scope of the invention which is defined in the appended claims.

Having thus set forth the nature of the invention, what is claimed is:

1. A structure for use in making a reclosable container comprising,

an elongated flexible closed integral tube of a flexible plastic film,and first and second interlocking elements integral with the tube on thesurface thereof shaped for cooperative pressure interengagement and forforcible separation,

said elements spaced apart from each other in both circumferentialdirections,

said film including a body forming sheet portion between theinterlocking elements at one side of the first element for forming thebody of a bag formed from the tube,

and said film including a flange forming sheet portion between theinterlocking elements at the other side of said first element which maybe subsequently separated axially along its length between the first andsecond elements for providing access to the bag formed from the tube andproviding a separate opening gripping flange for each element.

2. In combination,

an elongate closed flexible integral tube of a flexible plastic film,

a rib element extending axially along within said tube,

a groove element extending axially along within said tube,

said rib and groove elements being complementary shaped to interlockwith the application of force 4; to the outer surface of the tube at theelements and to separate when forcibly drawn apart, said elements beinginterlocked to hold the opposing sides of the tube together and to holdthe elements in their interlocked relationship, said elemcntsspacedapart from each other in both circumferential directions, said filmincluding a body forming sheet portion between the interlocking elementsat one side of the first element for forming the body of a bag formedfrom the tube, and said film including a flange forming sheet portionbetween the interlocking elements at the other side of said firstelement which may be subsequently separated axially along its lengthbetween the first and second elements for providing access to the bagformed from the tube and providing a separate opening gripping flangefor each element. 3. In combination, an elongated closed flexibleintegral tube of a flexible plastic film, first and second rib elementsextending axially along within said tube, first and second grooveelements extending axially along within said tube, said first rib andgroove elements and said second rib and groove elements beingcomplementary shaped and positioned to be capable of being interlockedwith the application of force to the outer surface of the tube at theelement and to separate when forcibly drawn apart,

said elements spaced apart from each other in circumferentialdirections, said film including body forming sheet portions positionedoutside of elements when interlocked to be at one side of each of themale elements for forming the bodies of bags formed from the tube, andsaid film including flange forming sheet portions being between theelements when interlocked and being at the other side of each of themale elements and which may be subsequently separated axially alongtheir length for providing a separate opening gripping flange for eachelement. 4. A structure for use in making a reclosable containercomprising,

an elongated flexible closed integral tube of a flexible plastic film,and first and second interlocking elements integral with the tube on thesurface thereof shaped for cooperative pressure interengagement and forforcible separation, said first interlocking element being arrowheadshaped in cross section and said second interlocking element beingshaped to form a groove to embrace and interlock with said firstelement, said elements spaced apart from each other in bothcircumferential directions, said film including a body forming a sheetportion between the interlocking elements at one side of the firstelement for forming the body of a bag formed from the tube, and saidfilm including a flange forming sheet portion between the interlockingelements at the other side of said first element which may besubsequently separated axially along its length between the first andsecond elements for providing access to the bag formed from the tube andproviding a separate opening gripping flange for each element. 5. Astructure for use in making a reclosable container comprising,

an elongated flexible closed integral tube of a flexible plastic film,and first and second interlocking elements integral with the tube on thesurface thereof shaped for cooperative pressure interengagement and forforcible separation,

said elements spaced apart from each other in both circumferentialdirections,

said film including a body forming sheet portion between theinterlocking elements at one side of the first element for forming thebody of a bag formed from the tube,

said film including a flange forming sheet portion between theinterlocking elements at the other side of said first element which maybe subsequently separated axially along its length between the first andsecond elements for providing access to the bag formed from the tube andproviding a separate opening gripping flange for each element,

and said flexible plastic film being of substantially uniform thicknessfor said flange portion and said body portion.

6. A structure for use in making a reclosable container,

comprising,

an elongated flexible closed integral tube of a flexible plastic film,and

first and second interlocking elements integral with the tube on thesurface thereof shaped for cooperative pressure interengagement and forforcible separation,

said interlocking elements being on the inner surface of said tube andprojecting therefrom, said elements spaced apart from each other in bothcircumferential directions,

said film including a body forming sheet portion between theinterlocking elements at one side of the first element for forming thebody of a bag formed from the tube,

References Cited by the Examiner UNITED STATES PATENTS 1,981,059 11/1934Matthews et al 156-251 2,461,976 2/1949 Schenk 264- 2,564,093 8/ 1951Bijl 138-177 2,674,289 4/1954 Silverman -3 2,740,740 4/ 1956 Binnal156-251 2,746,502 5/ 1956 Graell 150-3 2,750,631 6/1956 Johnson 264-953,038,205 6/1962 Plummer 138-166 3,088,495 5/1963 Svec 138-128 FOREIGNPATENTS 548,789 11/1957 Canada.

LAVERNE D. GEIGER, Primary Examiner.

ALEXANDER H. BRODMERKEL, LEWIS J. LENNY,

Examiners.

A. LEAVITT, C. HOUCK, Assistant Examiners.

1. A STRUCTURE FOR USE IN MAKING A RECLOSABLE CONTAINER COMPRISING, ANELONGATED FLEXIBLE CLOSED INTEGRAL TUBE OF A FLEXIBLE PLASTIC FILM, ANDFIRST AND SECOND INTERLOCKING ELEMENTS INTEGRAL WITH THE TUBE ON THESURFACE THEREOF SHAPED FOR COOPERATIVE PRESSURE INTERENGAGEMENT AND FORFORCIBLE SEPARATION, SAID ELEMENTS SPACED APART FROM EACH OTHER IN BOTHCIRCUMFERENTIAL DIRECTIONS, SAID FILM INCLUDING A BODY FORMING SHEETPORTION BETWEEN THE INTERLOCKING ELEMENTS AT ONE SIDE OF THE FIRSTELEMENT FOR FORMING THE BODY OF A BAG FORMED FROM THE TUBE,